Blocking-layer cell



Patented Aug. 3? 1948l I IBLGCKING-LAYER. CELL Johannes Jacobus Annen-usPloos van Amstel. Eindhoven, Netherlands, amener to Hturtforellllatignal Bank dr Trust @n.martiord, Conn... as

rus lee r amistades swimmer so, reis, sensi no. crasse In theNetherlands :mw ywhen' 7, 1942 section i, reune new est. ausser s. ieeePatent expirer Demher 7, 1962 v i @laluna (@l; it-366) a i 2 Inblocking-layer cells constituted by a earinvention provides aconstruction in which these rier plate, a semi-conductive electrode, abloclndrawbacks are obviated. ing layer, a thin conductive electrode'applied According to the invention the conductive electhereto(hereinafter briefly referred to -as trede is covered with an inertintermediate layer, blocking-layer cell of the selenium type), in 5 vonthe other side oi which lies the metal on which a supply conductor issoldered to the'latv which or in which the supply conductor is seter,several drawbacks are encountered in rev cured. The term "inert has tobe understood gard of the properties of the conductive electrode here tomean that the material does not disadat the point where the supplyconductor is sol vantageously react with or act upon the metal dered toit. s 10 o the conductive electrode. The intermediate These drawbacksparticularly occur when the layer may consist, for example, of iron,aluminmetal of the conductive layer easily alloys with lum or cinc. Themetal of the conductive electhe soldering metal. 1n fact, since theccetrece may in this case consist of cold, bismuth, ductive layer isvery thin, this layer will entirely mmny 0r u bismuth-anthony alloy. Thedissolve in the soldering .metal when itis epis letter metals have beenfound to be particularly plied to it so that at this place the specificprop... suitable for the manufacture of measuring cells. erties of thecell, which are a function of the AS it Solding matell use may be made0f the metal of the conductive electrode. may change @walled e110? 103.Consisting ci tin, cadmium completely in dependence of the solderingmetal. und bismuth- These drawbacks might be @imaged .by ghe Accordingto another form ci' construction the use of a press-contact, but ln thiscase there is intermediate layer may consist 0f a lgcquel l again thedanger that the conductive electrode MWF- AS a lacquer ethyl'ceuulcsecan Very Wen might be pressed through and deteriorated, be usedme?hmdenmg the lacquer layer is which leads to instability and even toshort-cin covered with u thin layer of metal, on which or @uiting of theeen. r v lin which the supply conductor is secured. As is Thesedrawbacks chiefly occur` with bloclsingwelb'known' m this case it is Vetpossible to 0b' layer Geus of vsmall Size L e ,with those WMS@ v tain aconductive connection between the underconductive electrodes have asurface smaller than myeur'; hem@ me conductive electmde of the mm?,amongst others the so-called measmimgmyer ceu" and the metal laye uringcells, since with these measuring cells the '30 The surface 0f theluiluer layer will genermetal of the conductive electrode has tosatisl'iotbb Mmed tg th of thefcondluctwe elic fy particularrequirements which serve to eive r u m er e Ose a nger s e' a definitevariation to the characteristic of the Particularly m the @me that thelatter exhibits Y cell. In the case oi' larger cells, however, it genavery small Surface' this saves much trouble erally sulce's to reinforcethe conductive layer 35 It has now been found with these cells that onapplying the metal on which or in which the at the place vhere tihisuplyafndultor mut supply wire is secured, even when it occupies a besecured' mater a den c o t at o t e larger surface than that of the'conductive elecconductive layer may there be used for the soltrode, thecapacity substantiall does not indering. Besides, in Gase the solderedConil@ crease. may 'be accountedyfor the tact exhibits a small surfacerelatively to the l that the lacquer'layer has a thickness which issurface of the whole cell. S0 that the influence great relatively to thethickness of the blocking upon the characteristic is small, if a changeof layer,

the Conductive electrode WOuld Occur, provided These steps are veryappropriate to be applied that this Change C1065 11011 impair thebreakdown d5 to cells. the conductive electrode of which convoltage.sists of gold and has a surface smaller than Another dimculty involvedwith measuring cells 30 mm.

is that the electrode is frequently so small that In arder that theinvention may be more clearly it is dicult t0 keep the solderingmaterial solely understood and readily carried into eii'ect, it willwithin this surface. When it passes outside this be described more fullywith reference to the .acsurface, then in the ilrst place the solderingcompenying drawing.

metal will start to serve as an electrode, result- Figure 1 shows ablocking-layer cell in which ing in a variation of the characteristiccurve, a layer of .inert metal is applied to the conductive whilst inaddition the capacity oi the cell inelectrode whereas creases in adetrimental manner. The present du Figure 2 shows a blocking-4ever cellin which various layers in the correctV proportions.

the celi'is enveloped by a thin lacquer layer which has the supplyconductor secured to it.

Both figures represent the cells on a greatlyenlarged scale and onlydiagrammaticaily.

The blocking-layer cell shownA -in Figure 1 comprises a carrier plate lwhich has a selenium layer 2 applied to it. This selenium layer hasformed on it a genetic or a non-genetic blocking layer 3 which hasapplied to it a conductive electrode 4 of gold having a small surface,for example of 1 mm. in diameter. This gold electrode has applied to i'tby vaporisation a thin layer of iron 5 which has secured to it a supplyconductor 8 by means of a small quantity of solder 1. Since gold doesnot alloy with iron, the good properties of the gold electrode arethusensured, but it is evident that in view of the small size of theseparts there is a great danser that the iron or the soldering material lmay pass outside the boundaries of the gold electrode. These drawbacksare largely suppressed by the construction shown in Figure 2. Theblocking-layer cell shown in this gure comprises, as before, a carrierVplate I. a selenium layer 2. a blocking layer 3 and a con-` ductive goldelectrode l. After the blocking-layer cell has been built up so far, itis dipped in lacquer, for which purpose ethyl cellulose is appropriate.The hardened lacquer layer. which is indicated by 8, has applied to it athin layer 9 of alloy 103 in which a supply wire 6 is secured.

The thickness of the lacquer layer is estimated to be of the order ofmagnitude of 10 microns. It appears that in such a lacquer layer suchapertures still exist that the metal layers on each side of the lacquerlayer are in contact with one another. However. rthe lacquer layerprevents the conductive electrode from being dissolved. from forming analloy or from being changed inany other way.\\.\ l

When use is made of the invention the thickness of the conductiveelectrode may be chosen much thinner-'up to 10 times thinner-than itused to be.

The :ligure does not show the thickness of ltltile e blocking layer'ismuchY thinner than can be shown in the figure. It is evident that due tothe small thicknessof this blocking layer relatively to the thicknessofthe lacquer layer the capacity of the cell is fullydetermined by thesurface of the electrode 4 and not by that of the quantity of metal 9.

What I claimis:

1 A blocking-layer cell, comprising a carrier plate. a semi-conductiveelectrode, a .blocking layer, a lconductive electrode applied to saidblocking layer, an intermediate layer of inert material deposited on atleast a portion of the exposed surface of said conduct-ive electrode, ametal contact layer applied to said intermediate layer. and a supplyconductor secured to said metal contact layer.

2. A blocking-layer cell as claimed in claim 1, in which theintermediate layer consists of a metal which is chemically inert towardssaid conductive electrode.

-3. A blocking-layer cell as claimed in claim 1. in which theintermediate layer consists of a lacquer layer.

4. A blocking-layer cell as claimed in claim 1. in which theintermediate layer consists of ethylcellulose.

5. A blocking-layer cell as claimed in claim 1, in which theintermediate layer covers a substantially greater surface than thesurface area of the `conductive electrode.

6. A blocking-layer cell as claimed in claim 1,

in which the layer of metal to which the supplyl conductor is securedalso covers a surface area which is larger than the surface area of theconductive electrode, and smaller than the surface area oftheintermediate layer.

7.l A blocking-layer cell as claimed in .claim-1, in which theconductive electrode consists of gold and has a surface smaller than 30mm3.

JOHANNES JACOBUS ASUERUS PLOOS VAN AMSTEL.

REFERENCES CITED The following references are of record in the

